bug fix for native kerberos libraries

[Christos Zoulas]

Hello,

This simple fix allows kerberos authentication to work with:

	-Dsun.security.jgss.native=true

and microsoft's sqljdbc 4.0.2206.100 driver.

Enjoy,

christos

--- a/java/src/sun/security/jgss/GSSUtil.java   Mon Oct 15 17:43:08 2012 -0400
+++ b/java/src/sun/security/jgss/GSSUtil.java   Mon Oct 15 17:44:28 2012 -0400
@@ -333,10 +333,19 @@
                         Subject accSubj = Subject.getSubject(acc);
                         Vector<GSSCredentialSpi> result = null;
                         if (accSubj != null) {
-                            result = new Vector<GSSCredentialSpi>();
                             Iterator<GSSCredentialImpl> iterator =
                                 accSubj.getPrivateCredentials
                                 (GSSCredentialImpl.class).iterator();
+                            // GSSCredentialImpl is only implemented in
+                            // the non-native kerberos implementation,
+                            // so if we don't get any elements here
+                            // assume native and return null so that
+                            // searchSubject does not fail. A better
+                            // fix is to implement the code that handles
+                            // this in native java.
+                            if (!iterator.hasNext())
+                                return null;
+                            result = new Vector<GSSCredentialSpi>();
                             while (iterator.hasNext()) {
                                 GSSCredentialImpl cred = iterator.next();
                                 debug("...Found cred" + cred);